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Green ring on tenon

Posted: Tue Nov 10, 2020 8:17 pm
by PaulT
I noticed a thin green ring on the slide tenon of my trombone located just on the slide side of the tightening nut (looking for all the world as if it were a thin green rubber ring gasket or something).

I cleaned it off using my wife's toothbrush. (just kidding, it was my kid's toothbrush) (just kidding, but it was a brush).

I understand that when brass oxidizes, the reaction is green. What I don't know is if this is something I should do anything about. Should I continue to brush the green residue off periodically back to the brass? Do I leave it alone and not concern myself with it? Do I put a thin layer of slide grease either on the entire tenon or the on the affected portion of the tenon? If I continue to remove the green residue as it appears, do I continue with a toothbrush or use a fine grade of steel wool to do a better (?) job of it?

I'll hang up and listen. Thanks.

Re: Green ring on tenon

Posted: Tue Nov 10, 2020 8:19 pm
by Elow
Dont do anything abrasive to it, or use grease. All trombones get it, i don’t worry about it.

Re: Green ring on tenon

Posted: Tue Nov 10, 2020 9:54 pm
by Posaunus
Elow wrote: Tue Nov 10, 2020 8:19 pm All trombones get it, ...
None of mine exhibit this. I don't think it's ubiquitous. If I had this schmutz appear, I'd immediately clean it off as part of my regular trombone hygiene protocol.

Re: Green ring on tenon

Posted: Tue Nov 10, 2020 10:48 pm
by Elow
Posaunus wrote: Tue Nov 10, 2020 9:54 pm
Elow wrote: Tue Nov 10, 2020 8:19 pm All trombones get it, ...
None of mine exhibit this. I don't think it's ubiquitous. If I had this schmutz appear, I'd immediately clean it off as part of my regular trombone hygiene protocol.
That’s very strange, every trombone i’ve got has gotten a green ring around. The newer looking slides are just like a week old and the 3B was ultrasonic cleaned last month. It’s no biggie and comes off every ultrasonic clean.

Re: Green ring on tenon

Posted: Tue Nov 10, 2020 11:53 pm
by Posaunus
Perhaps the Florida humidity?

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 12:35 am
by BGuttman
Posaunus wrote: Tue Nov 10, 2020 11:53 pm Perhaps the Florida humidity?
More likely salty air.

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 12:48 am
by Elow
Maybe, now im curious to the OP's climate

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 8:11 am
by JohnL
Elow wrote: Wed Nov 11, 2020 12:48 am Maybe, now im curious to the OP's climate
His profile says North Dakota. Not a lot of salty air around there.

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 11:18 am
by PaulT
North Dakota, but we're only 1,600 miles from the Gulf.


If salt and moisture are involved the phenomenon, then I will hazard a guess that the source of both is my sweat. And my grip is involved with the transfer. The ring was just above the nut on the part of the tenon not protected by the nut... and this area happens to rest in the crook of my hand. My sweat; my grip.

(I use a NeoTech grip on this horn)_

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 11:50 am
by PaulT
So, if I'm right, either I purchase a pair of those nice white gloves I see included with so many fine instruments or I incorporate a wipe down of the affected area to my "horn put away" routine. (I am good with the slide, but I haven't been, it appears, a good grip area wiper downer.)

I could put a thin layer of slide grease underneath tenon nut. It wouldn't affect the "grip portion" of the tenon. ?

Or, even put very thin layer of slide grease on the entire tenon (as long as the required "gripping" is still effective. ?

Re: Green ring on tenon

Posted: Wed Nov 11, 2020 12:32 pm
by BGuttman
Don't grease the part of the tenon that has to mate with the bell receiver. Other areas are fair game.

For the bell nut threads I would recommend candle wax instead of grease.